2 1/2 inch dual exhaust on 68 Delta 88

[bwalat]

Well now...I found that elusive "s" manifold..thanks to this board! I also have the duals-compatible shifter linkage.

Now, the only question I have is this: can I use 2 1/2 inch pipes for the exhausts? The ports measure 2 1/2 inches across.

[rocketraider]

A good custom exhaust shop (not Midas) should be able to bend pipe to fit this car easy enough. Most all of them still have the Huth bending machine program cards. Get it done in aluminized pipe and it'll last and look nice longer.

Even if 2-1/2 won't bolt directly to the manifolds, the shop can probably start out with a short length of the correct size pipe and then enlarge it to 2-1/2 close to the manifold.

You'll find that many years Olds factory duals used two different size exhaust pipes from engine to muffler, and the pipes after the muffler are often smaller than the headpipes. You may lose just a little bit of low end torque with big pipes, and that's what you really need to get these boats moving.

What kind of mufflers are you thinking of? Flowmasters are gonna be some loud on a big car. Pretty sure Walker and others make a good low-restriction muffler for it.

[Oldsmaniac]

I would say the stock 2\1/4 pipe would be fine....With stock mufflers and no resonators it will be too loud for my ears unless ya want to let people know your arriving!